A number of studies show that a large number of people are physically too passive for maintaining their health. One considerable reason of the passivity is excessive sitting. Office workers sit in chairs by their office desks many hours a day. The workers should occasionally stand up to work. Almost all new desks have a provision for height adjustment. Not many do use this feature for doing their work standing up, because standing still on a hard floor feels difficult and will stress legs and back. E.g. padded carpets have been introduced to the market to address this issue. They do make standing somewhat easier, but legs do still not move and standing still will soon cause the muscles to go numb.
One solution is a slightly curved board e.g. under product name Active Stand. This product allows some movement for legs and numbing can be reduced. A disadvantage of this evenly curved board is that standing on the curved surface causes the joints of ankles and knees to bend to a wrong position. A longer period of standing on a curved surface can cause stress problems to especially those having previous issues with ankle and knee joints. When rocking the board, the bending increases and the issue gets worse. The issue is further emphasized, if conventional, unstable level-surfaced balance boards with rocking movement in all directions are used. The disadvantage of the current curved rigid board is the rigidity of the board also causing the above-mentioned even tension in legs and the muscles above legs. It is possible to vary the points of tension by rocking the board but during rocking it is nearly impossible to e.g. use the keyboard, whereby work is interrupted during the rocking, thus causing a lower work efficiency.